Capacitive Sensors for Electronic Devices and Methods of Forming the Same

ABSTRACT

Capacitive sensor assemblies for electronic devices, and methods of forming capacitive sensor assemblies. The capacitive sensor assembly may include a top component having an intermediate layer formed on the top component, a bottom component positioned opposite the top component, a silicone layer positioned between the top component and the bottom component, and a first electrical trace positioned adjacent the silicone layer.

TECHNICAL FIELD

The disclosure relates generally to electronic sensors, and moreparticularly to capacitive sensor assemblies for electronic devices, andmethods of forming the capacitive sensor assemblies.

BACKGROUND

Conventional electronic devices typically include a variety of distinctinput devices formed from a plurality of components. For example,conventional electronic devices typically include a touch display toallow a user to interact with the device. Touch displays typicallyinclude a plurality of sensor assemblies that may be positioned insidethe casing of the electronic device. The sensor assemblies may be usedto detect when a user touches an external surface of the electronicdevice with the desire to interact with the device. When the sensorassemblies detect a user's touch, the sensor assemblies may send anelectrical input signal to distinct portions of the electronic device.

Conventional sensor assemblies include a plurality of layers and/orcomponents to detect the user's touch or interaction with the electronicdevice. However, as the number of layers and/or components increase inthe sensor assemblies, so does the required space for housing theassembly within the electronic device. That is, as the number of layersand/or components increase in the sensor assemblies, the over heightand/or z-space of the sensor assemblies also increases.

Additionally, a bond must be formed between all layers and/or componentsof the conventional sensor assemblies. With an increase in the layersand/or components, the likelihood of a bonding of the assembly to comeundone or uncoupled increases. Where two layers or components of thesensor assembly come uncoupled, the sensor assembly may have reducedoperational function, or may become inoperable.

SUMMARY

Generally, embodiments discussed herein are related to electronicsensors, and more particularly to capacitive sensor assemblies forelectronic devices, and methods of forming the capacitive sensorassemblies. The capacitive sensor assemblies discussed herein may reducethe number of layers and/or components forming the assembly by utilizinga silicone layer positioned between electrical traces, and/or formingthe electrical traces within or out of pre-existing layers of theelectronic device. By utilizing a silicone layer within the capacitivesensor assembly, a strong bond may be formed between the silicone layerand the distinct layers and/or components of the capacitive sensorassembly and/or components of the electronic device. Additionally, byforming the electrical traces of the capacitive sensor assembly withinor out of pre-existing layers of the electronic device, the number oflayers or components of the capacitive sensor assembly may be reduced,and the height or z-space of the capacitive sensor assembly may bereduced. As a result of the reduce number of layers or components, therisk of operational fault or failure may be reduced or eliminated.Additionally, as a result of the reduced height of the capacitive sensorassembly, the overall height and size of the electronic deviceimplementing the capacitive sensor assembly may also be reduced.

One embodiment may take the form of a method of manufacturing acapacitive sensory assembly in an electronic device. The method maycomprise coupling a silicone layer to a bottom portion of a housing ofthe electronic device, positioning a first electrical trace within aflex layer, the flex layer positioned on the silicone layer, oppositethe bottom portion of the housing, and curing the silicone layer to theflex layer including the first electrical trace. The method may alsocomprise applying an adhesive to the flex layer including the firstelectrical trace, opposite the silicone layer, and coupling a cover ofthe electronic device to the flex layer using the applied adhesive.

An additional embodiment may take the form of a method of manufacturinga capacitive sensory assembly in an electronic device. The method maycomprise coupling an intermediate layer on a at least a portion of aninner surface of a cover of the electronic device, etching a portion ofthe intermediate layer to form a first electrical trace in the etchedportion, positioning a silicone layer between the intermediate layer anda bottom portion of a housing of the electronic device, and curing thesilicone layer to the intermediate layer including the first electricaltrace.

Another embodiment may take the form of an electronic device comprisinga housing having a top portion, and a bottom portion coupled to the topportion. The electronic device may also comprise a capacitive sensorassembly positioned within the housing. The capacitive sensor comprisesa silicone layer positioned between the top portion and the bottomportion of the housing, a flex layer coupled to the silicone layer, anda first electrical trace positioned within the flex layer.

A further embodiment may take the form of an electronic devicecomprising a housing, a cover glass coupled to the housing, anintermediate layer formed on an inner surface of the cover glass, and acapacitive sensor assembly positioned between the housing and the coverglass. The capacitive sensor comprising a silicone layer coupled to theintermediate layer formed on the inner surface of the cover glass, and afirst electrical trace positioned within the intermediate layer,adjacent the silicone layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like structural elements, and in which:

FIG. 1 depicts an illustrative perspective view of a portion of awearable electronic device, according to embodiments.

FIG. 2 depicts an illustrative cross-section side view of a portion ofthe electronic device of FIG. 1 including a capacitive sensor assembly,taken along line CS-CS, according to embodiments.

FIG. 3 depicts a flow chart of an example process for forming acapacitive sensor assembly for an electronic device, according toembodiments.

FIGS. 4A-4D depict illustrative cross-section side views of a portion ofthe electronic device of FIG. 1 and various components of a capacitivesensor assembly undergoing the process depicted in FIG. 3, according toembodiments.

FIG. 5 depicts an illustrative cross-section side view of a portion ofthe electronic device of FIG. 1 including a capacitive sensor assembly,taken along line CS-CS, according to additional embodiments.

FIG. 6 depicts a flow chart of another example process for forming acapacitive sensor assembly for an electronic device, according toadditional embodiments.

FIGS. 7A-7D depict illustrative cross-section side views of a portion ofthe electronic device of FIG. 1 and various components of a capacitivesensor assembly undergoing the process depicted in FIG. 6, according toadditional embodiments.

FIG. 8 depicts an illustrative cross-section side view of a portion ofthe electronic device of FIG. 1 including a capacitive sensor assembly,taken along line CS-CS, according to further embodiments.

FIG. 9 depicts a flow chart of an additional example process for forminga capacitive sensor assembly for an electronic device, according tofurther embodiments.

FIGS. 10A-10C depict illustrative cross-section side views of a portionof the electronic device of FIG. 1 and various components of acapacitive sensor assembly undergoing the process depicted in FIG. 9,according to further embodiments.

It is noted that the drawings of the invention are not necessarily toscale. The drawings are intended to depict only typical aspects of theinvention, and therefore should not be considered as limiting the scopeof the invention. In the drawings, like numbering represents likeelements between the drawings.

DETAILED DESCRIPTION

Reference will now be made in detail to representative embodimentsillustrated in the accompanying drawings. It should be understood thatthe following descriptions are not intended to limit the embodiments toone preferred embodiment. To the contrary, it is intended to coveralternatives, modifications, and equivalents as can be included withinthe spirit and scope of the described embodiments as defined by theappended claims.

The following disclosure relates generally to electronic sensors, andmore particularly to capacitive sensor assemblies for electronicdevices, and methods of forming the capacitive sensor assemblies.

The capacitive sensor assemblies discussed herein may reduce the numberof layers and/or components forming the assembly by utilizing a siliconelayer positioned between electrical traces, and/or forming theelectrical traces within or out of pre-existing layers of the electronicdevice. By utilizing a silicone layer within the capacitive sensorassembly, a strong bond may be formed between the silicone layer and thedistinct layers and/or components of the capacitive sensor assemblyand/or components of the electronic device. Additionally, by forming theelectrical traces of the capacitive sensor assembly within or out ofpre-existing layers of the electronic device, the number of layers orcomponents of the capacitive sensor assembly may be reduced, and theheight or z-space of the capacitive sensor assembly may be reduced. As aresult of the reduce number of layers or components, the risk ofoperational fault or failure may be reduced or eliminated. Additionally,as a result of the reduced height of the capacitive sensor assembly, theoverall height and size of the electronic device implementing thecapacitive sensor assembly may also be reduced.

These and other embodiments are discussed below with reference to FIGS.1-10C. However, those skilled in the art will readily appreciate thatthe detailed description given herein with respect to these Figures isfor explanatory purposes only and should not be construed as limiting.

FIG. 1 shows an illustrative perspective view of a portable or wearableelectronic device 100 (hereafter, “electronic device”), according toembodiments. Electronic device 100, as shown in FIG. 1, may beconfigured to provide health-related information or data such as but notlimited heart rate data, blood pressure data, temperature data, oxygenlevel data, diet/nutrition information, medical reminders,health-related tips or information, or other health-related data. Theelectronic device may optionally convey the health-related informationto a separate electronic device such as a tablet computing device,phone, personal digital assistant, computer, and so on. In addition,electronic device 100 may provide additional information, such as butnot limited to, time, date, health, statuses or externally connected orcommunicating devices and/or software executing on such devices,messages, video, operating commands, and so forth (and may receive anyof the foregoing from an external device), in addition tocommunications.

Electronic device 100 may include a housing 102 at least partiallysurrounding a display 104 and one or more buttons 106 or input devices.The housing 102 may form an outer surface or partial outer surface andprotective case for the internal components of electronic device 100,and may at least partially surround the display 104. The housing 102 maybe formed of one or more components operably connected together, such asa front piece and a back piece. Alternatively, the housing 102 may beformed of a single piece operably connected to the display 104. Housing102 may formed from a plurality of distinct materials including, but notlimited to: corundum, commonly referred to as sapphire, glass orplastic. As discussed herein, and in another example, housing 102 may beformed from an electrically conductive material, or a material havingelectrically conductive properties.

Display 104 may be implemented with any suitable technology, including,but not limited to, a multi-touch sensing touchscreen that uses liquidcrystal display (LCD) technology, light emitting diode (LED) technology,organic light-emitting display (OLED) technology, organicelectroluminescence (OEL) technology, or another type of displaytechnology.

Button 106 may include any conventional input/output (I/O) device forelectronic device 100. Specifically, button 106 may include an actuationcomponent in electronic and/or mechanical communication with theinternal components of electronic device 100, to provide user inputand/or allow the user to interact with the various functions ofelectronic device 100. In an embodiment button 106 may be configured asa single component surrounded by housing 102. Alternatively, button 106may include a plurality of components, including an actuation component,in mechanical/electrical communication with one another and/or internalcomponent of electronic device 100. Button 106 may likewise include asensor, such as a biometric sensor, touch sensor, or the like.

Housing 102 may also have recesses 108 formed on opposite ends toconnect a wearable band 110 (partially shown in FIG. 1) to electronicdevice 100. Wearable band 110 may be used to secure wearable electronicdevice 100 to a user, or any other object capable of receivingelectronic device 100. In a non-limiting example where electronic device100 is a smart watch, wearable band 110 may secure the watch to a user'swrist. In other non-limiting examples, electronic device 100 may secureto or within another part of a user's body.

A cover 112 may be positioned above the touchscreen of display 104. Thatis, and as discussed herein, cover 112 may be positioned above thetouchscreen of display 104 and may be at least partially positionedwithin an opening of housing 102 and coupled to housing 102. Cover 112may protect display 104 from containments, without obstructing a user'sview and/or ability to interact with display 104 and/or electronicdevice 100. As such, cover 112 may be transparent or translucent, fullyor partially, in certain embodiments. As discussed herein, cover 112 maybe formed corundum, commonly referred to as sapphire. However, it isunderstood that cover 112 may be formed from any suitable transparentmaterial and/or combination of suitable transparent material including,but not limited to, ceramics, alumina, chemically strengthened glass,and reinforced plastic.

FIG. 2 depicts an enlarged cross-section front view of a portion ofelectronic device 100 of FIG. 1 taken along line CS-CS, according to anembodiment. With respect to this particular embodiment, FIG. 2 shows across-section front view of a portion of housing 102 and cover 112 ofelectronic device 100. Electronic device 100 may also include anintermediate layer 118 formed on at least a portion inner surface 120 ofcover 112. Intermediate layer 118 formed on cover 112 may be positionedwithin an opening 122 formed between cover 112 and housing 102, and maynot be exposed in electronic device 100. Intermediate layer 118 may beoptically dense and/or substantially translucent or opaque, such that auser of electronic device 100 may not be able to see through the portionof cover 112 positioned above intermediate layer 118. In a non-limitingexample shown in FIG. 2, and as a result of the optical properties,intermediate layer 118 may be positioned around a perimeter of cover 112to define an interactive area of electronic device 100, adjacent theintermediate layer 118. The interactive area of electronic device 100may include the touch screen of display 104 (see, FIG. 1), as discussedherein.

Intermediate layer 118 may be formed from a variety of materials. In anon-limiting example, intermediate layer 118 may be formed from an inkmaterial. The ink material may be deposited on inner surface 120 ofcover 112 using any suitable deposition technique or process including,but not limited to, painting, spraying, mask-and-ink submersion and thelike. In another non-limiting example, intermediate layer 118 may beformed as a substantially solid material layer. In the non-limitingexample, the substantially solid material layer may be formed as aplastic layer that may be coupled to inner surface 120 of cover 112. Theplastic layer may be coupled to the inner surface 120 using any suitablecoupling technique or process (e.g., bonding, welding, melting, and soon).

Electronic device 100 may also include a capacitive sensor assembly 124positioned within housing 102. In a non-limiting example shown in FIG.2, capacitive sensor assembly 124 may be substantially positionedbetween cover 112 and a bottom portion or component 126 of housing 102.As discussed herein, bottom portion or component 126 may be formed fromdistinct material and/or a distinct component than the remainder ofhousing 102. Capacitive sensor assembly 124 may be in electricalcommunication with display 104 and/or additional components ofelectronic device 100, and may be configured to detect input provide toelectronic device 100 via cover 112. That is, when a force is applied toouter surface 128 of cover 112 to interact with display 104 (see,FIG. 1) and/or other components of electronic device 100, cover 112 maysubstantially deflect and/or flex toward bottom portion or component 126of housing 102. As a result, capacitive sensor assembly 124 may sense ordetect the deflection of cover 112 to provide an input to electronicdevice 100.

Capacitive sensor assembly 124 may include a silicone layer 130positioned within opening 122 of electronic device 100. Silicone layer130 may be positioned between intermediate layer 118 formed on innersurface 120 of cover 112 and housing 102, and in the non-limitingexample shown in FIG. 2, silicone layer 130 may be coupled directly tobottom portion or component 126 of housing 102. As discussed herein,silicone layer 130 may be coupled to bottom portion or component 126using any suitable coupling technique including, but not limited to,injection molded, cured, adhered or the like. In certain embodiments,the silicone layer 130 may mechanically couple adjacent layers to oneanother, such as the adjacent layers shown in FIG. 2 and subsequentfigures, such as bottom component 126 and flex layer 132.

Silicone layer 130 may also be substantially compliant, flexible and/orelastic. As a result, when a force is applied to cover 112, siliconelayer 130 may substantially deform to allow electrical traces ofcapacitive sensor assembly 124 to move toward each other to vary acapacitance between the traces, and ultimately generate an electricalsignal to be sent to electronic device 100 based on the applied force,as discussed herein. Additionally, the physical properties complianceand/or elasticity of silicone layer 130 may allow portions of capacitivesensor assembly 124 (e.g., electrical traces) to return to a neutralstate (e.g., “spring-back” to an uncompressed position) relativelyrapidly, thereby permitting the detection of a consecutively-appliedforces being applied to cover 112 of electronic device 100. Further, andas discussed herein, silicone layer 130 may be positioned between twoelectrical traces of capacitive sensor assembly 124 to separate thetraces in order to detect the force applied to cover 112.

Capacitive sensor assembly 124 may also include a flex layer 132. In anon-limiting example shown in FIG. 2, flex layer 132 may be positionedbetween silicone layer 130 and intermediate layer 118. As discussedherein, flex layer 132 may be bonded and/or coupled to silicone layer130 of capacitive sensor assembly 124 using a variety of coupling orbonding techniques (e.g., adhesive, curing, and so on). Additionally, anadhesive 134 may be used to couple flex layer 132 to intermediate layer118 of electronic device 100. In the non-limiting example shown in FIG.2, adhesive 134 may be a pressure sensitive adhesive that may completelycover flex layer 132 and may be positioned between flex layer 132 andintermediate layer 118 to couple or bond flex layer 132 to cover 112 viaintermediate layer 118. The use of adhesive 134 to bond flex layer 132to intermediate layer 118 and/or cover 112, as well as the otherconnections, couplings and/or bonds formed between the various layers orcomponents of capacitive sensor assembly 124, may result in a hermeticseal being formed within electronic device 100.

Similar to silicone layer 130 of capacitive sensor assembly 124, flexlayer 132 may include substantially compliant, flexible and/or elasticproperties. In a non-limiting example, flex layer may be formed from anelastomeric material. As a result, and as discussed herein with respectto silicone layer 130, when a force is applied to cover 112, flex layer132 may also deform and/or flex toward bottom portion or component 126.Additionally, when the force on cover 112 is removed or discontinued,flex layer 132 may return or “spring-back” to a neutral state (e.g.,uncompressed position).

A first electrical trace 136 may be positioned or formed within flexlayer 132 of capacitive sensor assembly 124. In a non-limiting exampleshown in FIG. 2, first electrical trace 136 may be positioned withinflex layer 132 coupled to silicone layer 130, such that first electricaltrace 136 may be positioned between silicone layer 130, and intermediatelayer 118 and/or cover 112 of electronic device 100. First electricaltrace 136 may have capacitive characteristics and/or first electricaltrace 136 may be formed from an electrically conductive material, forexample copper. Although only a single first electrical trace 136 isshown in FIG. 2, it is understood that capacitive sensor assembly 124may include a group of electrical traces forming first electricaltrace(s) 136.

In the non-limiting example shown in FIG. 2, and as discussed herein,first electrical trace 136 may be a driven capacitive trace that maycooperate with an additional electrical trace of capacitive sensorassembly 124 to detect a force applied to cover 112 of electronic device100 by measuring changes in capacitance between the cooperatingelectrical traces of capacitive sensor assembly 124. By measuring thechanges in capacitance, capacitive sensor assembly 124 may detect theforce applied to cover 112 and may subsequently provide an electricalsignal to display 104 and/or additional components of electronic device100, as discussed herein.

As discussed herein, bottom portion or component 126 of housing 102 maybe formed from a distinct component or material from the remainder ofhousing 102 of electronic device 100. Where capacitive sensor assembly124 includes only a single electrical trace (e.g., first electricaltrace 136) formed between cover 112 and bottom portion or component 126of housing 102, bottom portion or component 126 may form a cooperatingelectrical trace for first electrical trace 136. In a non-limitingexample shown in FIG. 2, bottom portion or component 126 of housing 102may be formed from an electrically conductive material (e.g., copper)and may provide a cooperating electrical trace structure for firstelectrical trace 136. Where first electrical trace 136 forms a drivencapacitive trace, bottom portion or component 126 may form a sensecapacitive trace that may cooperate with first electrical trace 136.

First capacitive sensor assembly 124 may detect a force applied to cover112 by measuring the change in capacitance between first electricaltrace 136 and the cooperating electrical trace formed by bottom portionor component 126 of housing 102. In a non-limiting example, a continuouscharge or current may be provided to both first electrical trace 136 andbottom portion or component 126. The charge or current may provide apredetermined steady-state or uncompressed, measurable capacitancebetween first electrical trace 136 and bottom portion or component 126.When a force is applied to cover 112 of electronic device 100, cover112, flex layer 132 and/or silicone 130 may deflect and/or may flextoward bottom portion or component 126 of housing 102, as discussedherein. This may also cause first electrical trace 136 to deflect towardbottom portion or component 126 of housing 102, resulting in thedistance and the capacitance between first electrical trace 136 andbottom portion or component 126 to change. When the capacitance betweenfirst electrical trace 136 and bottom portion or component 126 changes,capacitive sensor assembly 124 may detect that a force has been appliedto cover 112, and may subsequently send an electrical signal to display104 and/or distinct components of electronic device 100.

FIG. 3 depicts an example process for forming a capacitive sensorassembly for an electronic device. Specifically, FIG. 3 is a flowchartdepicting one example process 200 for forming a capacitive sensorassembly having cooperating electrical traces formed from a firstelectrical trace and an electrically conductive housing. In some cases,process 200 may be used to form one or more capacitive sensorassemblies, as discussed above with respect to FIG. 2.

In operation 202, a silicone layer is coupled or bonded to a bottomportion or component of a housing. In operation 204, a first electricaltrace may be positioned within a flex layer positioned on the siliconelayer. In operation 206, the silicone layer may be cured or bonded tothe flex layer including the first electrical trace. In operation 208,an adhesive may be applied to the flex layer including the firstelectrical trace. In operation 210, a cover or top portion or componentof the housing may be adhered to the flex layer using the appliedadhesive.

FIGS. 4A-4D show capacitive sensor assembly 124 for electronic device100 (see, FIG. 4D) undergoing various operations that may be performedin accordance with process 200 of FIG. 3. It is understood thatsimilarly numbered components may function in a substantially similarfashion. Redundant explanation of these components has been omitted forclarity.

As shown in FIG. 4A, silicone layer 130 may be coupled or bonded to aportion of bottom portion or component 126 of housing 102. Siliconelayer 130 may be coupled or bonded to bottom portion or component 126using a variety of bonding techniques. In a non-limiting example,silicone material forming silicone layer 130 may be injection moldedonto bottom portion or component 126 of housing 102. In anothernon-limiting example, silicone layer may be die-cut to shape andsubsequently installed or positioned on bottom portion or component 126of housing 102. The die-cut silicone layer 130 may be positioned onbottom portion or component 126 in a uncured state. Silicone layer 130may be subsequently cured to bottom portion or component 126 immediatelyafter being positioned on housing 102, or during a subsequent curingprocess involving silicone layer 130 and distinct layers of capacitivesensor assembly 124, as discussed herein. The coupling or bonding ofsilicone layer 130 to bottom portion or component 126 shown in FIG. 4Amay correspond to operation 202 in FIG. 2.

FIG. 4B shows first electrical trace 136 positioned within flex layer132 positioned over silicone layer 130. First electrical trace 136 maybe positioned within flex layer 132 using a variety of techniques. In anon-limiting example, a portion of the material forming flex layer 132may be deposited over silicone layer 130 using any suitable materialdeposition technique, and first electrical trace may be positioned overthe portion of flex layer 132 deposited on silicone layer 130.Subsequent to positioning first electrical trace 136 on the depositedportion of the material forming flex layer 132, the remaining materialused to form flex layer 132 may be deposited over first electrical trace136. In another non-limiting example, flex layer 132 may be formed oversilicone layer 130, and a trench may be formed in a portion of flexlayer 132 to receive first electrical trace 136. In the non-limitingexample, first electrical trace 136 may be positioned within the trench,and additional material used to form flex layer 132 may fill in theremaining portion of the trench. The positioning of first electricaltrace 136 within flex layer 132 shown in FIG. 4B may correspond tooperation 204 in FIG. 2.

FIG. 4B may also show silicone layer 130 cured to flex layer 132including first electrical trace 136. In a non-limiting example, housing102, silicone layer 130 and flex layer 132 including first electricaltrace 136 may undergo a curing process to cure or bond silicone layer130 to flex layer 132. Additionally, and as discussed herein withrespect to FIG. 4A, silicone layer 130 may undergo the curing process tocure or bond silicone layer 130 to bottom portion or component 126 ofhousing 102. The curing of silicone layer 130 to flex layer 132including first electrical trace 136 shown in FIG. 4B may correspond tooperation 206 in FIG. 2.

FIG. 4C shows an adhesive 134 applied to flex layer 132. In thenon-limiting example shown in FIG. 4C, adhesive 134 may be applied tothe entire exposed surface of flex layer 132 to ensure a desired bond isachieved between flex layer 132 and subsequent components of electronicdevice 100 (e.g., cover 112). As discussed herein, adhesive 134 may be apressure sensitive adhesive. Additionally, adhesive 134 may take theform of any medium associated with adhesives including, but not limitedto, tape, spray and paste. The applying of adhesive 134 to flex layer132 shown in FIG. 4C may correspond to operation 208 in FIG. 2.

FIG. 4D shows cover 112 adhered to flex layer 132 using adhesive 134. Inthe non-limiting example shown in FIG. 4D, intermediate layer 118 formedon inner surface 120 of cover 112 may be coupled directly to adhesive134 to couple cover 112 to flex layer 132. Where adhesive 134 is formedas a pressure sensitive adhesive, cover 112 may be pressed into adhesive134 to form the bond and/or to adhere cover 112 to flex layer 132. Byadhering cover 112 to flex layer 132 using adhesive 134, a hermetic sealmay be formed within electronic device 100 between cover 112, housing102 and the various layers and components of capacitive sensor assembly124. The hermetic seal may prevent debris, such as dust or water, fromentering electronic device 100 and causing damage to the internalcomponents of electronic device 100. The adhering of the cover 112 toflex layer 132 using adhesive 134 shown in FIG. 4D may correspond tooperation 210 in FIG. 2.

FIG. 5 depicts an enlarged cross-section front view of a portion ofelectronic device 100 of FIG. 1 taken along line CS-CS, according toanother embodiment. Electronic device 100 shown in FIG. 5 includes acapacitive sensor assembly 324 having a distinct configuration fromcapacitive sensor assembly 124 discussed herein with respect to FIGS.2-4D. It is understood that similarly numbered and/or named componentsof electronic device 100 and capacitive sensor assembly 324 may functionin a substantially similar fashion. Redundant explanation of thesecomponents has been omitted for clarity.

As shown in FIG. 5, and as similarly discussed herein with respect toFIG. 2, first electrical trace 336 may be positioned or formed withinflex layer 332. However, distinct from first electrical trace 136 ofFIG. 2, first electrical trace 336, and flex layer 332, may bepositioned between silicone layer 330 and bottom portion or component126 of housing 102. As shown in the non-limiting example of FIG. 5, flexlayer 332 may be coupled to bottom portion or component 126 of housing102 using adhesive 334. Additionally, flex layer 332 including firstelectrical trace 336 may be coupled or cured to silicone layer 330 ofcapacitive sensor assembly 324. As a result of the position of flexlayer 332 in capacitive sensor assembly 324, and distinct fromcapacitive sensor assembly 124 of FIG. 2, silicone layer 330 may bedirectly coupled to or cured to intermediate layer 118 formed on innersurface 120 of cover 112.

Also distinct from capacitive sensor assembly 124 of FIG. 2, capacitivesensor assembly 324 may include a second electrical trace 338. In thenon-limiting example shown in FIG. 5, second electrical trace 338 may bepositioned within intermediate layer 118 formed on inner surface 120 ofcover 112. Additionally, second electrical trace 338 may be positionedbetween silicone layer 330 and cover 112, and may also be positionedadjacent silicone layer 330, opposite first electrical trace 336positioned within flex layer 332. Similar to first electrical trace 336,second electrical trace 338 may have capacitive characteristics and/orsecond electrical trace 338 may be formed from an electricallyconductive material, for example copper. Although only a single firstelectrical trace 336 and second electrical trace 338 are shown in FIG.5, it is understood that one or both of the electrical traces ofcapacitive sensor assembly 324 may include a group of electrical tracesforming first electrical trace(s) 336 and/or second electrical trace(s)338.

As discussed herein, second electrical trace 338 may be positioned orformed within intermediate layer 118 using any suitable laser etchingprocesses. In a non-limiting example, and discussed in detail herein, alaser etching process used to form second electrical trace 338 mayinclude a laser direct structuring (LDS) process. As a result of usingan LDS process, intermediate layer 118 may be formed from athermoplastic material that may be doped with metal-plastic additives.

Second electrical trace 338 of capacitive sensor assembly 324 may be adriven capacitive trace that may cooperate with first electrical trace336 to detect a force applied to cover 112 by measuring changes incapacitance between the first electrical trace 336 and second electricaltrace 338, as discussed herein. In the non-limiting example shown inFIG. 5, where second electrical trace 338 is a driven capacitive trace,first electrical trace 336 may be a sense capacitive trace that maycooperate with second electrical trace 338. As similarly discussedherein with respect to first electrical trace 136 and bottom portion orcomponent 126 in FIG. 2, first electrical trace 336 and secondelectrical trace 338 of capacitive sensor assembly 324 may be utilizedwithin electronic device 100 to detect a force applied to cover 112 bymeasuring a change in capacitance between the respective electricaltraces 336, 338.

As a result of capacitive sensor assembly 324 including secondelectrical trace 338, bottom portion or component 126 of housing 102 maynot be required to cooperate with first electrical trace 336 in order tomeasure a change in capacitance. As such, housing 102, and specifically,bottom portion or component 126 may be formed from any suitable materialfor electronic device, and may not necessarily be formed from a materialhaving electrically conductive properties.

FIG. 6 depicts an example process for forming a capacitive sensorassembly for an electronic device. Specifically, FIG. 6 is a flowchartdepicting one example process 400 for forming a capacitive sensorassembly having cooperating electrical traces formed from a firstelectrical trace and a second electrical trace. In some cases, process400 may be used to form one or more capacitive sensor assemblies, asdiscussed above with respect to FIG. 5.

In operation 402, an intermediate layer may be coupled to an innersurface of a cover for an electronic device. In operation 404, a portionof the intermediate layer may be etched to form an electrical trace. Inoperation 406, a distinct electrical trace positioned within a flexlayer is bonded to the intermediate layer using a silicone layer. Inoperation 408, an adhesive may be applied to the flex layer includingthe distinct electrical trace. In operation 410, a bottom portion orcomponent of the housing may be adhered to the flex layer using theapplied adhesive.

FIGS. 7A-7D show capacitive sensor assembly 324 for electronic device100 (see, FIGS. 7C and 7D) undergoing various operations that may beperformed in accordance with process 400 of FIG. 6. It is understoodthat similarly numbered components may function in a substantiallysimilar fashion. Redundant explanation of these components has beenomitted for clarity.

As shown in FIG. 7A, intermediate layer 118 may be coupled to innersurface 120 of cover 112. Intermediate layer 118 may be formed from avariety of materials, and as such, may be coupled and/or applied tocover 112 using various techniques. In a non-limiting example,intermediate layer 118 may be formed from an ink material. The inkmaterial may be deposited on inner surface 120 of cover 112 using anysuitable deposition technique or process including, but not limited to,painting, spraying, mask-and-ink submersion and the like. In anothernon-limiting example, intermediate layer 118 may be formed as asubstantially solid material layer. In the non-limiting example, thesubstantially solid material layer may be formed as a plastic layer thatmay be coupled to inner surface 120 of cover 112. The plastic layer maybe coupled to the inner surface 120 using any suitable couplingtechnique or process (e.g., bonding, welding, melting, and so on).Furthermore, and as discussed in detail with respect to FIG. 7B,intermediate layer 118 may be formed from a thermoplastic material thatmay be doped with metal-plastic additives. The metal-plastic additivesmay be activated and/or react when exposed to a laser beam. The couplingof intermediate layer 118 to inner surface 120 of cover 112 shown inFIG. 7A may correspond to operation 402 in FIG. 6.

FIG. 7B shows intermediate layer 118 having undergone an etching processto form second electrical trace 338. Various etching processes may beperformed on intermediate layer 118 to form second electrical trace 338.In a non-limiting example, intermediate layer 118 may undergo a laserdirect structuring (LDS) process. During the LDS process, a portion ofintermediate layer 118, formed from thermoplastic material having dopedmetal-plastic additives, may be exposed to a laser. The laser may causethe metal-plastic additives to react or activate, which may result inthe exposed portions of intermediate layer 118 to change in chemicalcomposition. The intermediate layer 118 may be subsequently dunked in abath of a metal material (e.g., copper), where the exposed portions ofintermediate layer 118 may attract the metal material to form secondelectrical trace 338. In another non-limiting embodiment, intermediatelayer 118 may be masked and subsequently etched to form a trench in aportion of intermediate layer 118. Conductive material (e.g., copper)may then be deposited within the trench formed in intermediate layer 118to form second electrical trace 338. The etching of intermediate layer118 to form second electrical trace 338 shown in FIG. 7B may correspondto operation 404 in FIG. 6.

FIG. 7C shows flex layer 332 including first electrical trace 336coupled or bonded to intermediate layer 118 via silicone layer 330. Thatis, flex layer 332 may be coupled or bonded to silicone layer 330, andintermediate layer 118 may also be coupled or bonded to silicone layer330 opposite flex layer 332. In the non-limiting example, silicone layer330 may be coupled or bonded to intermediate layer 118 including secondelectrical trace 338 using a variety of bonding techniques. In anon-limiting example, silicone material forming silicone layer 330 maybe injection molded onto intermediate layer 118. In another non-limitingexample, silicone layer 330 may be die-cut to shape and subsequentlyinstalled or positioned on intermediate layer 118. The die-cut siliconelayer 330 may be positioned on intermediate layer 118 in a uncuredstate. Silicone layer 330 may be subsequently cured to intermediatelayer 118 immediately after being positioned on intermediate layer 118,or during a subsequent curing process involving silicone layer 330 anddistinct layers of capacitive sensor assembly 324, as discussed herein.

As similarly discussed herein with respect to FIG. 4B, first electricaltrace 336 may be positioned within flex layer 332 using a variety oftechniques. In a non-limiting example, a portion of the material formingflex layer 332 may be deposited over silicone layer 330 using anysuitable material deposition technique, and first electrical trace 336may be positioned over the portion of flex layer 332 deposited onsilicone layer 330. Subsequent to positioning first electrical trace 336on the deposited portion of the material forming flex layer 332, theremaining material used to form flex layer 332 may be deposited overfirst electrical trace 336. In another non-limiting example, flex layer332 may be formed over silicone layer 330, and a trench may be formed ina portion of flex layer 332 to receive first electrical trace 336. Inthe non-limiting example, first electrical trace 336 may be positionedwithin the trench, and additional material used to form flex layer 332may fill in the remaining portion of the trench.

Additionally, and also discussed herein with respect to FIG. 4B,silicone layer 330 may be cured to flex layer 332 including firstelectrical trace 336. In a non-limiting example, cover 112, intermediatelayer 118, silicone layer 330 and flex layer 332 including firstelectrical trace 336 may undergo a curing process to cure or bondsilicone layer 330 to flex layer 332. Silicone layer 330 may undergo thecuring process to cure or bond silicone layer 330 to intermediate layer118 formed on cover 112. The coupling or bonding of flex layer 332and/or silicone layer 330 to intermediate layer 118 shown in FIG. 7C maycorrespond to operation 406 in FIG. 6.

FIG. 7C may also show an adhesive 334 applied to flex layer 332. In thenon-limiting example shown in FIG. 7C, adhesive 334 may be applied tothe entire exposed surface of flex layer 332 to ensure a desired bond isachieved between flex layer 332 and subsequent components of electronicdevice 100 (e.g., bottom portion or component 126 of housing 102). Asdiscussed herein, adhesive 334 may be a pressure sensitive adhesive.Additionally, adhesive 334 may take the form of any medium associatedwith adhesives including, but not limited to, tape, spray and paste. Theapplying of adhesive 334 to flex layer 332 shown in FIG. 7C maycorrespond to operation 408 in FIG. 6.

FIG. 7D shows bottom portion or component 126 of housing 102 adhered toflex layer 332 using adhesive 334. In the non-limiting example shown inFIG. 7D, bottom portion or component 126 may be coupled directly toadhesive 334 to couple housing 102 to flex layer 332. Where adhesive 334is formed as a pressure sensitive adhesive, bottom portion or component126 may be pressed into adhesive 334 to form the bond and/or to adherehousing 102 to flex layer 332. By adhering housing 102 to flex layer 332using adhesive 334, a hermetic seal may be formed within electronicdevice 100 between cover 112, housing 102 and the various layers andcomponents of capacitive sensor assembly 324. The adhering of the bottomportion or component 126 of housing 102 to flex layer 332 using adhesive334 shown in FIG. 7D may correspond to operation 410 in FIG. 6.

FIG. 8 depicts an enlarged cross-section front view of a portion ofelectronic device 100 of FIG. 1 taken along line CS-CS, according to afurther embodiment. Electronic device 100 shown in FIG. 8 includes acapacitive sensor assembly 524 having a distinct configuration fromcapacitive sensor assembly 124, 324 discussed herein with respect toFIGS. 2-4D, and 5-7D, respectively. It is understood that similarlynumbered and/or named components of electronic device 100 and capacitivesensor assembly 524 may function in a substantially similar fashion.Redundant explanation of these components has been omitted for clarity.

As shown in FIG. 8, and as similarly discussed herein with respect toFIG. 5, an electrical trace of capacitive sensor assembly 524 may formedin intermediate layer 118 formed on inner surface 120 of cover 112. Inthe non-limiting example shown in FIG. 8, first electrical trace 536 maybe formed in intermediate layer 118. Similar to capacitive sensorassembly 124 of FIG. 2, and dissimilar to capacitive sensor assembly 324of FIG. 5, capacitive sensor assembly 524 may not include a second,distinct electrical trace formed between cover 112 and housing 102. Assuch, and as similarly discussed herein with respect to FIG. 2, bottomportion or component 126 of housing 102 may be formed from anelectrically conductive material and may act as a cooperating electricaltrace for first electrical trace 536 positioned within intermediatelayer 118. First electrical trace 536 positioned within intermediatelayer 118 and bottom portion or component 126 of housing 102 may detecta force applied to cover 112 by measuring a change in capacitancebetween electrical trace 536 and bottom portion or component 126, asdiscussed herein with respect to FIG. 2. Redundant explanation of thesefunctions have been omitted for clarity.

Dissimilar to capacitive sensor assembly 124 of FIG. 2 and capacitivesensor assembly 324 of FIG. 5, capacitive sensor assembly 524 of FIG. 8may not include a flex layer (e.g., flex layer 132—FIG. 2; flex layer332—FIG. 5). In the non-limiting example where first electrical trace536 is positioned within intermediate layer 118 and bottom portion orcomponent 126 act as a cooperating electrical trace for first electricaltrace 536, flex layer may be removed from capacitive sensor assembly524. Additionally, because the flex layer may be removed from capacitivesensor assembly 524, the adhesive layer used to bond the flex layer tointermediate layer 118 (e.g., adhesive 134—FIG. 2) or housing 102 (e.g.,adhesive 334—FIG. 5) may also be removed from capacitive sensor assembly524. The removal of the flex layer and the adhesive layer may reduce thenumber of layers and the height of capacitive sensor assembly 524.Additionally, the removal of the flex layer and the adhesive layer fromcapacitive sensor assembly 524 may reduce the overall size and/or heightof electronic device 100 as well.

Silicone layer 530 may be coupled to intermediate layer 118 and housing102. In a non-limiting example shown in FIG. 8, and distinct fromsilicone layers 130, 330 in FIGS. 2 and 5, respectively, silicone layer530 may be coupled, bonded and/or cured to intermediate layer 118 formedon inner surface 120 of cover 112, and bottom portion or component 126of housing 102. As such, silicone layer 530 may be the only compliantlayer formed between first electrical trace 536 and bottom portion orcomponent 126, as the flex layer and the adhesive layer have beenremoved from capacitive sensor assembly 524.

FIG. 9 depicts an example process for forming a capacitive sensorassembly for an electronic device. Specifically, FIG. 9 is a flowchartdepicting one example process 600 for forming a capacitive sensorassembly having cooperating electrical traces formed from a firstelectrical trace and an electrically conductive housing. In some cases,process 600 may be used to form one or more capacitive sensorassemblies, as discussed above with respect to FIG. 8.

In operation 602, an intermediate layer may be coupled to an innersurface of a cover for an electronic device. In operation 604, a portionof the intermediate layer may be etched to form an electrical trace. Inoperation 606, a silicone layer may be cured to the intermediate layerand a bottom portion or component of a housing for the electronicdevice.

FIGS. 10A-10C show capacitive sensor assembly 524 for electronic device100 (see, FIG. 10C) undergoing various operations that may be performedin accordance with process 600 of FIG. 9. It is understood thatsimilarly numbered components may function in a substantially similarfashion. Redundant explanation of these components has been omitted forclarity.

As shown in FIG. 10A, intermediate layer 118 may be coupled to innersurface 120 of cover 112. Intermediate layer 118 may be formed from avariety of materials, and as such, may be coupled and/or applied tocover 112 using various techniques. In a non-limiting example,intermediate layer 118 may be formed from an ink material. The inkmaterial may be deposited on inner surface 120 of cover 112 using anysuitable deposition technique or process including, but not limited to,painting, spraying, mask-and-ink submersion and the like. In anothernon-limiting example, intermediate layer 118 may be formed as asubstantially solid material layer. In the non-limiting example, thesubstantially solid material layer may be formed as a plastic layer thatmay be coupled to inner surface 120 of cover 112. The plastic layer maybe coupled to the inner surface 120 using any suitable couplingtechnique or process (e.g., bonding, welding, melting, and so on).Furthermore, and as discussed in detail with respect to FIG. 7B,intermediate layer 118 may be formed from a thermoplastic material thatmay be doped with metal-plastic additives. The metal-plastic additivesmay be activated and/or react when exposed to a laser beam. The couplingof intermediate layer 118 to inner surface 120 of cover 112 shown inFIG. 10A may correspond to operation 602 in FIG. 9.

FIG. 10B shows intermediate layer 118 having undergone an etchingprocess to form first electrical trace 536. Various etching processesmay be performed on intermediate layer 118 to form first electricaltrace 536. In a non-limiting example, intermediate layer 118 may undergoa laser direct structuring (LDS) process. During the LDS process, aportion of intermediate layer 118, formed from thermoplastic materialhaving doped metal-plastic additives, may be exposed to a laser. Thelaser may cause the metal-plastic additives to react or activate, whichmay result in the exposed portions of intermediate layer 118 to changein chemical composition. The intermediate layer 118 may be subsequentlydunked in a bath of a metal material (e.g., copper), where the exposedportions of intermediate layer 118 may attract the metal material toform first electrical trace 536. In another non-limiting embodiment,intermediate layer 118 may be masked and subsequently etched to form atrench in a portion of intermediate layer 118. Conductive material(e.g., copper) may then be deposited within the trench formed inintermediate layer 118 to form first electrical trace 536. The etchingof intermediate layer 118 to form first electrical trace 536 shown inFIG. 10B may correspond to operation 604 in FIG. 9.

As shown in FIG. 10C, silicone layer 530 may be coupled, bonded or curedto a portion of intermediate layer 118 formed on cover 112 and bottomportion or component 126 of housing 102. Silicone layer 530 may becoupled, bonded or cured to intermediate layer 118 and housing 102 usinga variety of bonding techniques. In a non-limiting example, siliconematerial forming silicone layer 530 may be injection molded betweenintermediate layer 118 or bottom portion or component 126 of housing102. In another non-limiting example, silicone layer may be die-cut toshape and subsequently installed or positioned on intermediate layer 118or bottom portion or component 126 of housing 102. The die-cut siliconelayer 130 may be in an uncured state. Subsequent to positioning thedie-cut silicone layer 530, cover 112 including intermediate layer 118,bottom portion or component 126 of housing 102 and silicone layer 530may all undergo a curing process. The coupling, bonding or curing ofsilicone layer 530 to intermediate layer 118 and bottom portion orcomponent 126 shown in FIG. 10C may correspond to operation 606 in FIG.9.

Although discussed herein as a bottom portion or component of theexternal housing of the electronic device, it is understood that bottomportion or component 126 may not be a portion of housing 102, and/or maynot be external component of electronic device 100. In anothernon-limiting example, bottom component 126 may be a bottom component ofthe capacitive sensor assembly, and may be an internal component orstructure positioned within opening 122 formed between cover 112 andhousing 102. Additionally, cover may not include an external componentof electronic device 100, and/or may not be substantially transparent.Similar to bottom component 126, cover 112 may be a top component of thecapacitive sensor assembly, and may be an internal component orstructure positioned within opening 122 formed between cover 112 andhousing 102.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not target to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

We claim:
 1. A method of manufacturing a capacitive sensory assembly inan electronic device, the method comprising: coupling a silicone layerto a bottom portion of a housing of the electronic device; positioning afirst electrical trace within a flex layer, the flex layer positioned onthe silicone layer, opposite the bottom portion of the housing; curingthe silicone layer to the flex layer including the first electricaltrace; applying an adhesive to the flex layer including the firstelectrical trace, opposite the silicone layer; and coupling a cover ofthe electronic device to the flex layer using the applied adhesive. 2.The method of claim 1 further comprising coupling an intermediate layeron a at least a portion of an inner surface of the cover of theelectronic device.
 3. The method of claim 2, wherein the coupling of thecover to the flex layer further comprises adhering the intermediatelayer directly to the flex layer using the applied adhesive.
 4. Themethod of claim 1, wherein the coupling of the silicone layer to thebottom portion of the housing further comprises curing the siliconelayer to the housing.
 5. The method of claim 1 further comprisingforming the bottom portion of the housing of the electronic device froman electrically conductive material.
 6. A method of manufacturing acapacitive sensory assembly in an electronic device, the methodcomprising: coupling an intermediate layer on a at least a portion of aninner surface of a cover of the electronic device; etching a portion ofthe intermediate layer to form a first electrical trace in the etchedportion; positioning a silicone layer between the intermediate layer anda bottom portion of a housing of the electronic device; and curing thesilicone layer to the intermediate layer including the first electricaltrace.
 7. The method of claim 6 further comprising: bonding a flex layerto the silicone layer, opposite the intermediate layer; and positioninga second electrical trace within the flex layer.
 8. The method of claim7 further comprising: applying an adhesive to the flex layer includingthe second electrical trace, opposite the silicone layer; and adheringthe bottom portion of the housing of the electronic device to the flexlayer using the applied adhesive.
 9. The method of claim 6 furthercomprising curing the silicone layer to the bottom portion of thehousing of the electronic device.
 10. The method of claim 9 furthercomprising forming the bottom portion of the housing of the electronicdevice from an electrically conductive material.
 11. An electronicdevice comprising: a housing comprising: a top portion; and a bottomportion coupled to the top portion; and a capacitive sensor assemblypositioned within the housing, the capacitive sensor comprising: asilicone layer positioned between the top portion and the bottom portionof the housing; a flex layer coupled to the silicone layer; and a firstelectrical trace positioned within the flex layer.
 12. The electronicdevice of claim 11, wherein the flex layer and the first electricaltrace of the capacitive sensor assembly are positioned between the topportion of the housing and the silicone layer.
 13. The electronic deviceof claim 12, wherein the capacitive sensor assembly further comprises anadhesive positioned between the flex layer and top portion of thehousing, the adhesive bonding the flex layer to top portion of thehousing.
 14. The electronic device of claim 12, wherein the bottomportion of the housing is formed from an electrically conductivematerial.
 15. The electronic device of claim 12, wherein the siliconelayer of the capacitive sensor assembly is coupled directly to thebottom portion of the housing.
 16. The electronic device of claim 11,wherein the flex layer and the first electrical trace of the capacitivesensor assembly are positioned between the bottom portion of the housingand the silicone layer.
 17. The electronic device of claim 16, whereinthe capacitive sensor assembly further comprises a second electricaltrace positioned within an intermediate layer formed between the topportion of the housing and the silicone layer.
 18. The electronic deviceof claim 17, wherein the silicone layer of the capacitive sensorassembly is coupled directly to the intermediate layer.
 19. Anelectronic device comprising: a housing; a cover glass coupled to thehousing; an intermediate layer formed on an inner surface of the coverglass; and a capacitive sensor assembly positioned between the housingand the cover glass, the capacitive sensor comprising: a silicone layercoupled to the intermediate layer formed on the inner surface of thecover glass; and a first electrical trace positioned within theintermediate layer, adjacent the silicone layer.
 20. The electronicdevice of claim 19, wherein the housing is formed from an electricallyconductive material.
 21. The electronic device of claim 20, wherein thesilicone layer of the capacitive sensor is coupled to the housing. 22.The electronic device of claim 19, wherein the capacitive sensorassembly further comprises: a flex layer positioned between the siliconelayer and the housing; a second electrical trace positioned within theflex layer.
 23. The electronic device of claim 22, wherein thecapacitive sensor assembly further comprises an adhesive positionedbetween the flex layer and the housing, the adhesive bonding the flexlayer to the housing.